Resin grinding wheel for polishing hard alloy cutter and preparation method of resin grinding wheel

Abstract

The invention relates to the technical field of super-hard grinding tool preparation, in particular to a resin grinding wheel for hard alloy cutter polishing and a preparation method of the resin grinding wheel. Forming a bonding layer on the outer circumferential surface of the base body layer; forming an abrasive material layer on the outer circumferential surface of the bonding layer; wherein the abrasive material layer comprises the following raw materials in parts by weight: 45-55 parts of diamond abrasive particles, 12-18 parts of modified epoxy natural rubber, 3-5 parts of a sulfur-zinc oxide vulcanizing agent, 3-4 parts of a vulcanization accelerator, 20-30 parts of modified polyurethane and 1-3 parts of a nano dispersant, and the resin grinding wheel has the characteristics of low roughness and low grinding wheel wear ratio.

Description

Technical Field

[0001] This invention relates to the field of superhard abrasive preparation technology, and in particular to a resin grinding wheel for polishing cemented carbide tools and its preparation method. Background Technology

[0002] In the field of modern precision machining, cemented carbide cutting tools, with their superior Rockwell hardness of HRA89-93, are widely used in low-roughness machining in key areas such as aerospace, automotive manufacturing, and precision instruments. However, their Vickers hardness of 1300-1800 HV presents a significant challenge to surface polishing: traditional resin-bonded grinding wheels (such as conventional commercially available resin grinding wheels) often experience premature diamond abrasive grain detachment due to insufficient bond strength during machining, resulting in a wheel wear rate as high as 0.15-0.2 mm. 3 / mm 3 Meanwhile, due to the poor matching between the elastic modulus of the binder in the abrasive layer and that of the cemented carbide (the modulus of traditional resin is about 1.2-1.5 GPa, while that of cemented carbide is 500-600 GPa), it is easy to generate plough-like scratches with a depth of 3-5 μm on the workpiece surface, which makes it difficult for the surface roughness Ra value of the tool after polishing to meet the surface quality requirements of low roughness tools (such as mirror end mills and micro-diameter drills).

[0003] In existing technologies, although there have been attempts to improve the performance of binders by adding nanofillers (such as CNTs and SiO2), there are problems such as poor dispersibility and high cost (the price of nanofillers is 2000-3000 yuan / kg). Grinding wheels using ordinary epoxy-rubber composite binders are prone to binder softening during high-speed polishing (speed > 3000 rpm) due to insufficient crosslinking density (crosslinking point spacing > 10 nm), resulting in unstable abrasive grain exit height (fluctuation ± 20%), which seriously affects the processing accuracy.

[0004] Therefore, developing a resin-based polishing wheel that combines high bonding strength, suitable elastic modulus, and excellent abrasive grain holding power has become the key to solving the precision polishing problem of cemented carbide cutting tools. Summary of the Invention

[0005] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a resin grinding wheel for polishing cemented carbide tools and its preparation method. In view of the problems of defective binder performance, insufficient abrasive holding force and unstable machining accuracy in the prior art, this invention provides a high-performance resin grinding wheel with polishing efficiency improved by more than 30%, surface roughness reduced to Ra≤0.1μm and grinding wheel wear ratio≤0.1 and its preparation method.

[0006] The present invention first provides a method for preparing a resin grinding wheel for polishing cemented carbide tools, the method comprising the following steps: providing a substrate layer;

[0007] An adhesive layer is formed on the outer circumferential surface of the substrate layer;

[0008] An abrasive layer is formed on the outer circumferential surface of the adhesive layer;

[0009] The abrasive layer comprises the following raw materials in parts by weight:

[0010] 45-55 parts diamond abrasive

[0011] 12-18 parts of modified epoxy natural rubber

[0012] 3-5 parts of sulfur-zinc oxide sulfide

[0013] 3-4 parts of vulcanization accelerator

[0014] 20-30 parts of modified polyurethane

[0015] 1-3 parts of nano-dispersant.

[0016] Another aspect of the present invention provides a resin grinding wheel for polishing cemented carbide tools prepared by the method described above.

[0017] The resin grinding wheel for polishing carbide cutting tools provided by this invention has the following beneficial effects:

[0018] 1. Multi-stage toughening binder system

[0019] Modified epoxy natural rubber, through the rigid benzene ring structure introduced by methyl gallate (increasing Tg to 85℃), increases the glass transition temperature of the binder by 35℃ compared to traditional rubber-based binders (Tg=50℃), and maintains stable rigidity at high temperatures (deformation <0.1% during high-speed polishing at 3000rpm).

[0020] In modified polyurethane, fluorocarbon segments (surface energy ≤18mN / m) reduce the adhesion of abrasive chips, and the polar groups of chitosan (-OH, -NH2) form hydrogen bonds with the diamond surface (containing oxygen groups) (bond energy about 20-30kJ / mol), which increases the holding force of abrasive particles by 40% (pull-out force of a single abrasive particle ≥80N).

[0021] 2. Dynamically Adaptive Polishing Mechanism

[0022] The elastic modulus of the binder can be dynamically adjusted by the polyurethane content (1.8-2.5GPa) to form a modulus gradient of 1:200-1:300 with the cemented carbide (500GPa), effectively buffering the polishing pressure (contact stress ≤5MPa) and avoiding brittle fracture scratches.

[0023] Nano-alumina (specific surface area ≥100m²) 2 / g) is used as an abrasive dispersant to improve the uniformity of diamond distribution (dispersion ≥95%), control the average spacing of abrasive particles to 2-3 times the particle size, and achieve a material removal rate of (0.5-1.0mm). 3 The balance between ( / min) and surface quality.

[0024] 3. Low loss and long lifespan characteristics

[0025] The segmented hot-pressing process achieves a binder crosslinking density of 1.2 × 10⁻³ m³. o l / cm 3 (Traditional process: approximately 0.8 × 10⁻³ m) o l / cm 3 The wear rate was reduced to 0.06mm. 3 / mm 3 (Tested according to ISO 6106 standard), the service life is extended by 50% under the same processing conditions.

[0026] The shear strength of the bonding layer reaches 18MPa (GB / T 7124 standard), which is higher than the 12MPa of traditional grinding wheels, eliminating the risk of abrasive layer detachment and ensuring the safety of high-speed processing. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the resin grinding wheel for polishing cemented carbide tools according to the present invention;

[0028] Figure 2 This is a SEM image of the grinding wheel prepared in Example 1 of the present invention;

[0029] Figure 3 This is a SEM image of the grinding wheel prepared in Comparative Example 2 of this invention;

[0030] Figure 4 SEM image of synthetic single-crystal diamond in Embodiment 1 of this invention;

[0031] Figure 5 A photograph of the cemented carbide object processed by this invention after polishing. Detailed Implementation

[0032] This invention provides a low-roughness, low-damage resin grinding wheel for polishing carbide cutting tools. The resin grinding wheel includes a matrix layer, which is a high-strength matrix layer. The matrix layer is made of glass fiber reinforced phenolic resin, with a glass fiber content of 35-45 wt%. The thickness of the matrix layer is 3-5 mm. The outer circumferential surface of the matrix layer is sandblasted, resulting in a surface roughness of Ra 3.2-6.3 μm, which enhances adhesion. The matrix layer has a central hole for easy installation.

[0033] The resin grinding wheel includes an adhesive layer, which can be formed on the outer circumferential surface of the substrate layer. The adhesive layer is formed by applying an adhesive and then curing it. The adhesive can be an epoxy resin-silane coupling agent adhesive.

[0034] Furthermore, the outer circumferential surface of the substrate layer can be first coated with a silane coupling agent, such as KH-560, at a concentration of 2 wt%. After the silane coupling agent dries, the epoxy resin is coated on top. The epoxy resin can be a reinforced epoxy resin comprising a nano-silicon carbide reinforcing phase, with the nano-silicon carbide reinforcing phase comprising 10 wt%. The curing temperature of the adhesive can be 100-110℃, the curing pressure can be 0.5-0.6 MPa, the curing time can be 2-3 hours, and the thickness of the adhesive layer can be 50-100 μm. The shear strength of the adhesive layer can be greater than or equal to 15 MPa.

[0035] The resin grinding wheel includes an abrasive layer, which can be bonded to the outer circumferential surface of the substrate layer by the adhesive layer.

[0036] The thickness of the abrasive layer can be 2-4 mm, and the density of the abrasive layer is 1.8-2.0 g / cm³. 3 The abrasive layer includes diamond abrasive grains, which can be synthetic single-crystal diamonds. The particle size of the diamond abrasive grains can be 10-20μm, and the strength is greater than or equal to 130N.

[0037] The abrasive layer includes modified epoxy natural rubber, which acts as an adhesive. The preparation of the modified epoxy natural rubber can include a three-step process:

[0038] 1. Epoxidation modification stage: Methyl gallate (purity ≥98%) and epichlorohydrin were added to the reactor at a ratio of 1:0.6 (mass ratio), along with 0.8wt% benzyltriethylammonium chloride catalyst. The reaction was refluxed in an oil bath at 85℃ for 4.5h. The characteristic peak of the epoxy group (910 cm⁻¹) was detected by FT-IR. -1 The formation of substance A was confirmed.

[0039] 2. Graft copolymerization stage: Using N,N-dimethylformamide as solvent (solid content 20wt%), substance A and epoxidized natural rubber (epoxy degree 45-55%) are mixed at a mass ratio of 1.5:1, and 0.5wt% p-toluenesulfonic acid catalyst is added. The reaction is carried out at 110℃ for 2.5h. The degree of grafting is controlled by detecting the molecular weight distribution (Mw = 8000-12000) by gel permeation chromatography (GPC).

[0040] 3. Deprotection and activation stage: Dissolve the product in chloroform (concentration 15wt%), add excess sodium hydroxide (molar ratio 1:1.2), stir at 50℃ for 1h to carry out demethylation reaction, wash with water-ethanol precipitation-vacuum drying (60℃ / 12h) to obtain modified epoxy natural rubber containing active hydroxyl groups (hydroxyl content 0.8-1.2mmol / g).

[0041] The abrasive layer includes a sulfur-zinc oxide sulfiding agent. The mass ratio of sulfur to zinc oxide in the sulfur-zinc oxide sulfiding agent is 1:(2-3).

[0042] The abrasive layer includes modified polyurethane, which can serve as an elastic phase. The preparation of the modified polyurethane includes:

[0043] 1. Preparation of prepolymer: Under nitrogen protection, 12g of polycaprolactone diol (Mn=2000) and 4g of isophorone diisocyanate were added to the reactor and reacted at 85℃ for 2.5h. The NCO content was titrated to be 4.2wt%.

[0044] 2. Functionalization modification: Add 30ml of DMF for dilution, then add 0.6g of hexafluorocyclopentanediol and 0.4g of carboxymethyl chitosan in sequence, react at 50℃ for 2h, and confirm successful grafting by detecting the characteristic peaks of fluorine atoms and chitosan by 1H-NMR.

[0045] 3. Nanocomposite: Add 0.3g of oleophilic modified nano TiO2, ultrasonically disperse for 40min to obtain a uniform dispersion, and spray dry (inlet temperature 180℃) to obtain modified polyurethane particles (particle size 50-100μm).

[0046] The abrasive layer includes a nano-dispersant with a particle size of 50-100 nm, which may be nano-alumina, and has a specific surface area greater than or equal to 100 m². 2 / g. The various component raw materials in the abrasive layer need to be mixed and hot-pressed to prepare the abrasive layer.

[0047] The mixing process includes mixing raw materials using a twin-screw extruder with a length-to-diameter ratio of 30:1 and a rotational speed of 80-120 rpm. The mixing process can involve first crushing the modified epoxy natural rubber and modified polyurethane to 60-70 μm, then premixing them with diamond abrasive particles, sulfur-zinc oxide vulcanizing agent, vulcanization accelerator, and nano-dispersant at 80°C, and then melt-blending them at 120-125°C for 60-70 min to form a binder coating layer with a thickness of 5-10 μm on the surface of the diamond abrasive particles. The elemental distribution of the binder coating layer can be detected by SEM-EDS.

[0048] The hot pressing process includes segmented hot pressing on a fully automatic hot press. Diamond abrasive grains with a binder coating are placed into a mold inside the hot press and then heated and hot pressed. The pressure, temperature, and time parameters in the hot pressing process are shown in Table 1.

[0049] Table 1. Hot pressing molding pressure and temperature parameters.

[0050]

[0051] The present invention will be further illustrated by specific embodiments below.

[0052] In the following examples, the glass fiber reinforced phenolic resin is Japanese ASAHI RP1560, the epoxy resin in the epoxy resin-silane coupling agent binder is Japanese ASAHI R200, the commercially available ordinary polyurethane elastomer is Shandong Shengquan PU86, and the ordinary epoxidized natural rubber is Qingdao Soft Control SCR5.

[0053] Example 1

[0054] A resin grinding wheel includes a base layer, an adhesive layer, and an abrasive layer, wherein the abrasive layer is bonded to the outer circumferential surface of the base layer by the adhesive layer.

[0055] The matrix layer is made of glass fiber reinforced phenolic resin with a glass fiber content of 35%, a thickness of 3 mm, and a roughness Ra = 3.2 μm;

[0056] The adhesive layer uses an epoxy resin-silane coupling agent adhesive, and 10 wt% nano-silicon carbide is added to the epoxy resin.

[0057] The abrasive layer is 2mm thick, and the raw material weight distribution of the abrasive layer is as follows:

[0058] Diamond abrasive grains (10-20μm, strength 140N): 50 parts

[0059] Modified epoxy natural rubber: 15 parts

[0060] Sulfur-zinc oxide vulcanizing agent (1:2.5): 4 parts

[0061] Vulcanization accelerator DM (dibenzothiazole disulfide): 4 parts

[0062] Modified polyurethane: 25 parts

[0063] Nano-alumina: 2 parts

[0064] 1. Mixing: Crush the modified epoxy natural rubber and modified polyurethane to 60μm, add them to a twin-screw extruder with other raw materials and premix at 80℃ for 30min, then mix at 120℃ for 70min, and after cooling, crush to 20-40 mesh particles.

[0065] 2. Hot pressing:

[0066] Section 1: 80℃ / 1MPa / 60s, mold preheating and initial compaction;

[0067] Second stage: 100℃ / 3MPa / 130s, the binder began to melt and coat the abrasive particles;

[0068] Three-stage temperature control: 120℃ / 5MPa / 120s, with infrared temperature measurement to ensure uniform internal temperature.

[0069] Four stages: 125℃ / 6MPa / 15min, during the pressure holding stage, the mold expansion was measured to be <0.3%.

[0070] 3. Bonding treatment: After sandblasting the substrate surface, apply KH-560 solution, dry it, and then apply epoxy resin adhesive containing 10% nano silicon carbide. Cure at 100℃ for 2 hours to obtain a Φ200×30×32mm grinding wheel.

[0071] Example 2

[0072] Example 2 is similar to Example 1 in process, except that the content of modified polyurethane is 20 parts and the hot pressing pressure of the last section (four sections) is 5 MPa.

[0073] Example 3

[0074] Example 3 is similar to Example 1 in process, except that the content of modified polyurethane is 25 parts and the hot pressing pressure of the last section (four sections) is 6 MPa.

[0075] Example 4

[0076] Example 4 is similar to Example 1 in process, except that the content of modified polyurethane is 30 parts and the hot pressing pressure of the last section (four sections) is 7 MPa.

[0077] Example 5

[0078] A resin grinding wheel includes a base layer, an adhesive layer, and an abrasive layer, wherein the abrasive layer is bonded to the outer circumferential surface of the base layer by the adhesive layer.

[0079] The matrix layer is made of glass fiber reinforced phenolic resin with a glass fiber content of 45wt%, a thickness of 5mm, and a roughness Ra = 6.3μm;

[0080] The adhesive layer uses an epoxy resin-silane coupling agent adhesive, and 10 wt% nano-silicon carbide is added to the epoxy resin.

[0081] The abrasive layer is 2mm thick, and the raw material weight distribution of the abrasive layer is as follows:

[0082] Diamond abrasive grains (10-20µm, strength 140N): 45 parts

[0083] Modified epoxy natural rubber: 12 parts

[0084] Sulfur-zinc oxide vulcanizing agent (1:2.5): 3 parts

[0085] Vulcanization accelerator DM: 3 parts

[0086] Modified polyurethane: 20 parts

[0087] Nano-alumina: 1 part

[0088] 1. Mixing: Crush the modified epoxy natural rubber and modified polyurethane to 70μm, add them to a twin-screw extruder with other raw materials and premix at 80℃ for 30min, then mix at 125℃ for 60min, and after cooling, crush to 20-40 mesh particles.

[0089] 2. Hot pressing:

[0090] Section 1: 80℃ / 1MPa / 60s, mold preheating and initial compaction;

[0091] Second stage: 100℃ / 3MPa / 130s, the binder began to melt and coat the abrasive particles;

[0092] Three-stage temperature control: 120℃ / 5MPa / 120s, with infrared temperature measurement to ensure uniform internal temperature.

[0093] Four stages: 125℃ / 6MPa / 15min, during the pressure holding stage, the mold expansion was measured to be <0.3%.

[0094] 3. Bonding treatment: After sandblasting the substrate surface, apply KH-560 solution, dry it, and then apply epoxy resin adhesive containing 10% nano silicon carbide. Cure at 100℃ for 2 hours to obtain a Φ200×30×32mm grinding wheel.

[0095] Example 6

[0096] A resin grinding wheel includes a base layer, an adhesive layer, and an abrasive layer, wherein the abrasive layer is bonded to the outer circumferential surface of the base layer by the adhesive layer.

[0097] The matrix layer is made of glass fiber reinforced phenolic resin with a glass fiber content of 35%, a thickness of 3 mm, and a roughness Ra = 3.2 μm;

[0098] The adhesive layer uses an epoxy resin-silane coupling agent adhesive, and 10 wt% nano-silicon carbide is added to the epoxy resin.

[0099] The abrasive layer is 2mm thick, and the raw material weight distribution of the abrasive layer is as follows:

[0100] Diamond abrasive grains (10-20µm, strength 140N): 55 parts

[0101] Modified epoxy natural rubber: 18 parts

[0102] Sulfur-zinc oxide vulcanizing agent (1:2.5): 5 parts

[0103] Vulcanization accelerator DM: 3 parts

[0104] Modified polyurethane: 30 parts

[0105] Nano-alumina: 3 parts

[0106] 1. Mixing: Crush the modified epoxy natural rubber and modified polyurethane to 60μm, add them to a twin-screw extruder with other raw materials and premix at 80℃ for 30min, then mix at 120℃ for 70min, and after cooling, crush to 20-40 mesh particles.

[0107] 2. Hot pressing:

[0108] Section 1: 80℃ / 1MPa / 60s, mold preheating and initial compaction;

[0109] Second stage: 100℃ / 3MPa / 130s, the binder began to melt and coat the abrasive particles;

[0110] Three-stage temperature control: 120℃ / 5MPa / 120s, with infrared temperature measurement to ensure uniform internal temperature.

[0111] Four stages: 125℃ / 6MPa / 15min, during the pressure holding stage, the mold expansion was measured to be <0.3%.

[0112] 3. Bonding treatment: After sandblasting the substrate surface, apply KH-560 solution, dry it, and then apply epoxy resin adhesive containing 10% nano silicon carbide. Cure at 100℃ for 2 hours to obtain a Φ200×30×32mm grinding wheel.

[0113] Comparative Example 1

[0114] Comparative Example 1 is an unmodified binder grinding wheel (traditional process control).

[0115] A resin grinding wheel includes a base layer, an adhesive layer, and an abrasive layer, wherein the abrasive layer is bonded to the outer circumferential surface of the base layer by the adhesive layer.

[0116] The matrix layer is made of glass fiber reinforced phenolic resin with a glass fiber content of 35%, a thickness of 3 mm, and a roughness Ra = 3.2 μm;

[0117] The adhesive layer uses epoxy resin adhesive;

[0118] The abrasive layer is 2mm thick, and the raw material weight distribution of the abrasive layer is as follows:

[0119] Diamond abrasive grains (10-20µm, strength 140N): 50 parts

[0120] Ordinary epoxidized natural rubber (ungrafted): 15 parts

[0121] Sulfur-zinc oxide vulcanizing agent (1:2.5): 4 parts

[0122] Vulcanization accelerator DM: 4 parts

[0123] Commercially available ordinary polyurethane elastomer (non-fluorinated and chitosan modified): 25 parts

[0124] Nano-alumina dispersant: 0 parts (for removing nano-fillers)

[0125] Preparation steps:

[0126] 1. Mixing: Crush ordinary epoxidized natural rubber and commercially available polyurethane to 60μm, and directly mechanically mix with other raw materials (without using a twin-screw extruder for melt blending) for 30 minutes.

[0127] 2. Hot pressing: The traditional two-stage pressing method is adopted (first stage 90℃ / 2MPa / 100s, second stage 120℃ / 4MPa / 300s), without gradient pressure and temperature control.

[0128] 3. Adhesion treatment: The substrate surface is coated with ordinary epoxy resin adhesive only (without the addition of nano-reinforcing phase and coupling agent).

[0129] Comparative Example 2

[0130] Comparative Example 2 is a grinding wheel with missing key components.

[0131] A resin grinding wheel includes a base layer, an adhesive layer, and an abrasive layer, wherein the abrasive layer is bonded to the outer circumferential surface of the base layer by the adhesive layer.

[0132] The matrix layer is made of glass fiber reinforced phenolic resin with a glass fiber content of 35%, a thickness of 3 mm, and a roughness Ra = 3.2 μm;

[0133] The adhesive layer uses an epoxy resin-silane coupling agent adhesive, and 10 wt% nano-silicon carbide is added to the epoxy resin.

[0134] The abrasive layer is 2mm thick, and the raw material weight distribution of the abrasive layer is as follows:

[0135] Diamond abrasive grains (10-20µm, strength 140N): 50 parts

[0136] Modified epoxy natural rubber: 15 parts (epoxidation only, no deprotection, hydroxyl content 0.3 mmol / g)

[0137] Sulfur-zinc oxide vulcanizing agent (1:2.5): 4 parts

[0138] Vulcanization accelerator DM: 4 parts

[0139] Modified polyurethane: 25 parts (without carboxymethyl chitosan, fluorine-modified only)

[0140] Nano-alumina dispersant: 0 parts (for removing nano-fillers)

[0141] Preparation steps

[0142] 1. Mixing: The mixture was blended using a twin-screw extruder, but no nano-alumina dispersant was added. The mixing temperature was 110°C (lower than the mixing temperature in Example 1).

[0143] 2. Hot pressing: The four-stage process of Example 1 is used, but the pressure in the third stage is reduced to 4 MPa (20% lower than the pressure in Example 1).

[0144] The grinding wheels obtained from the above examples and comparative examples were subjected to performance tests, and the test results are shown in Table 2. The surface roughness test standard was GB / T 1031-2009, the grinding wheel wear ratio test standard was ISO 6106, the single abrasive grain holding force was tested using a self-made tensile testing device, the processing efficiency was tested using a constant pressure test, the bond layer shear strength test standard was GB / T 7124, and other standards were adopted from the company's own standards.

[0145] Table 2 Summary of Performance Comparison between Examples and Comparative Examples

[0146]

[0147]

[0148] As shown in Table 2, the unmodified binder in Comparative Example 1 lacks the chemical bonding between the active hydroxyl groups and diamond (interfacial energy difference > 15mN / m), resulting in a significant decrease in abrasive holding force. During polishing, abrasive particles fall off, causing scratches on the workpiece surface. The traditional two-stage pressing process causes uneven cross-linking of the binder, leading to a significant increase in wear rate.

[0149] In Comparative Example 2, the modified epoxy natural rubber lacked deprotection, resulting in insufficient hydroxyl content, which weakened the hydrogen bonding with diamond (bond energy decreased to 12 kJ / mol). The absence of nano-alumina led to uneven abrasive particle dispersion (SEM showed localized agglomeration regions with diameters >200 nm, see appendix). Figure 3 The high elastic modulus of the binder led to excessive polishing pressure, causing microcracks on the workpiece surface (AFM detected a crack defect with a depth of 2μm).

[0150] A comparison of Examples 1 and 2-4 revealed that the grinding wheel exhibited the best overall performance (lowest wear ratio and smallest roughness) when the polyurethane content was 25 parts and the pressure was 6 MPa, verifying the synergistic optimization effect of the formulation and process.

[0151] As can be seen from the above examples and comparative examples:

[0152] 1. Necessity of binder modification: Unmodified materials suffer from weak interfacial bonding and cross-linking structural defects, resulting in a significant decrease in polishing accuracy and grinding wheel life. This confirms the key role of the three-step modification process of this invention in improving abrasive grain holding force and binder stability.

[0153] 2. Importance of nanocomposite and gradient process: The lack of nano-dispersant and deviation of key process parameters will lead to uneven abrasive particle distribution and stress control failure, indicating that the nanocomposite mixing technology and four-stage hot pressing process proposed in this invention are the core elements for achieving high performance.

[0154] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in the present invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those skilled in the art. In addition to the specific methods, devices, and materials used in the embodiments, based on the knowledge of those skilled in the art and the description of the present invention, any prior art methods, devices, and materials similar to or equivalent to those described, used, and materials in the embodiments of the present invention can be used to implement the present invention. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for preparing a resin grinding wheel for polishing cemented carbide tools, characterized in that: The preparation method includes the following steps: Provide a matrix layer; An adhesive layer is formed on the outer circumferential surface of the substrate layer; An abrasive layer is formed on the outer circumferential surface of the adhesive layer; The abrasive layer comprises the following raw materials in parts by weight: 45-55 parts diamond abrasive 12-18 parts of modified epoxy natural rubber 3-5 parts of sulfur-zinc oxide sulfide 3-4 parts of vulcanization accelerator 20-30 parts of modified polyurethane 1-3 parts of nano-dispersant.

2. The preparation method according to claim 1, characterized in that: The preparation of the modified epoxy natural rubber includes: epoxidizing methyl gallate and epichlorohydrin in a mass ratio of 1:(0.5-0.7) under the action of a quaternary ammonium salt catalyst to obtain a first product; grafting the first product in a mass ratio of (1-2):1 with epoxy natural rubber in a polar solvent to obtain a second product; and introducing active hydroxyl groups into the second product through a deprotection reaction, wherein the hydroxyl content is 0.8-1.2 mmol / g.

3. The preparation method according to claim 1, characterized in that: The preparation of the modified polyurethane includes: reacting polycaprolactone diol and isophorone diisocyanate in a mass ratio of (2-4):1 to obtain a prepolymer, wherein the residual NCO in the prepolymer is 3-5%; reacting the prepolymer, hexafluorocyclopentanediol, and carboxymethyl chitosan in a mass ratio of (1-2):(1-1.5):1 to obtain a block copolymer of fluorinated elastic segments and chitosan polar segments; and adding nano-titanium dioxide to the block copolymer of fluorinated elastic segments and chitosan polar segments to obtain the modified polyurethane.

4. The preparation method according to claim 1, characterized in that: The preparation of the abrasive layer includes mixing, which involves crushing the modified polyurethane and modified epoxy natural rubber to a particle size of 60-70 μm, and then melt-blending them with diamond abrasive particles, sulfur-zinc oxide vulcanizing agent, vulcanization accelerator, and nano-dispersant.

5. The preparation method according to claim 4, characterized in that: The melt blending process involves blending at 115-135°C for 50-70 minutes using a twin-screw extruder.

6. The preparation method according to claim 5, characterized in that: After melt blending, a binder coating layer is formed on the surface of the diamond abrasive grains. The preparation of the abrasive layer includes segmented hot pressing of the diamond abrasive grains containing the binder coating layer. The segmented hot pressing parameters are shown in the table below. 。 7. The preparation method according to claim 1, characterized in that: The adhesive layer is formed by coating an adhesive and then curing it. The adhesive is an epoxy resin-silane coupling agent adhesive.

8. The preparation method according to claim 7, characterized in that: The adhesive comprises a reinforced epoxy resin, which includes nano-silicon carbide, and the thickness of the adhesive layer is 50-100 μm.

9. The preparation method according to claim 7, characterized in that: The curing temperature is 100-110℃, the curing pressure is 0.5-0.6MPa, and the curing time is 2-3h.

10. A resin grinding wheel for polishing cemented carbide tools prepared by any one of the preparation methods according to claims 1-9.

Images